"Changing States: Does it Matter?" Created by Doug Spicher
Elkridge Landing Middle School

Elkridge, Maryland

This lesson is designed for grade 7 or 8 and should take about 2-45 minute periods.





Substances change all around us. They change depending upon their chemical make-up and what is done to them.

For example, a physical change does not result in the formation of new substances. Physical changes alter only the size, shape, form or matter state of a material. Water boiling, melting ice, tearing paper, freezing water and crushing a can are all examples of physical changes.

On the other hand, chemical changes are a bit different. In a chemical change, a new substance is formed. The chemical change also usually involves heat, burning, or other interaction with energy. There are five rules of thumb that usually determine if a chemical change occurs:

In today's activity, you will see first hand the differences between chemical and physical changes, as well as attempt to detect the five characteristics of a chemical change.


Activity 1

Secure the following from the supply area:


From time to time, you will be required to secure additional materials from the supply area. Remember to never take the supply container to your lab station!

Activity 2a

Wear your goggles at all times!!! Fashion the aluminum foil into a trough, then call your teacher to light your candle.

Activity 2b

Perform each of the following as separate mini-activities, then fill in the chart that follows with either "physical change" or "chemical change". Do each, 1-7 by slowly moving the trough back and forth over the flame. Discard the trough contents prior to moving to the next part.

  1. Boil a drop of water in the foil trough.
  2. Place a bit of sugar in the trough and scorch it.
  3. Place a bit of flour in the trough and scorch it.
  4. Boil a drop of vinegar.
  5. Tear a sheet of paper.
  6. Put starch and water in your hand and mix it.
  7. Place a piece of paper in your trough and char it.
  8. Mix water and food coloring in the beaker.
  9. Add baking soda to the beaker. Stir.
  10. Add a few drops of vinegar to the beaker.

Remember to clean dry and return all equipment and to clean up your lab station.


Activity 3a

Fill in the following chart based upon activity 2b.



Physical or Chemical Change











Activity 3b

Choose any of the five tests you performed and state briefly why each is a physical or a chemical change.


Activity 4

Earlier, you read that a chemical change is indicated if a new material is formed. Yet dissolving salt in water makes salt water, but it is considered to be a physical change. Did somebody mess up? Explain.


Activity 5

Identify each as a physical or chemical change:

a. sifting flour-_____________________________

b. sharpening a pencil-___________________________

c. cooking an egg-_____________________________

d. burning charcoal-______________________________

e. melting ice-_________________________________

Activity 6

Your younger sibling is studying chemical and physical changes in school and is having a hard time with the concept. You decide to help giving the youngster more examples that he or she would understand. Using example not used in class, list and describe 7 physical and 7 chemical changes that a 3rd grader would understand.

End of Activity!


Student Resource Booklet for:

"Changing States...Does it Matter?"


Grade 8



Phases of Matter

All material objects are either solid, liquid or gas. All matter is made up of molecules. These vibrate vigorously at a certain distance from each other, determined by their internal energy. Temperature determines the phase (state) of the material. Water is liquid at room temperature 72° F/22.2° C. On the North and South Poles water freezes, forming large ice continents (solid). At the equator water evaporates rapidly into water vapor (gas).

Temperature is a measure of the average speed of molecules. The amount of heat energy present determines their speed. The more heat available, the faster the molecules will vibrate and the more separated they become from each other.

In truth, matter has four phases. The fourth state is plasma. As heat energy is applied, ice (solid) melts (liquid) and evaporates (gas). If heat continues to be applied to the gas, the atoms of gas become supercharged until the individual atoms break up. This means that the nuclei and the electrons break apart. The ejected particles (protons, neutrons and electrons) and their bonding energy become plasma. Plasma occurs only at temperatures around six million degrees Celsius, like the surface of our sun or other stars.

"Changing States: Does it Matter?" Created by Doug Spicher